Specificity of magnetoelectric effects in a new GdMnO3 magnetic ferroelectric

A complex study of the magnetic, electric, magnetoelectric, and magnetoelastic properties of GdMnO3 single crystals has been performed in the low-temperature region in strong pulsed magnetic fields up to 200 kOe. An anomaly of the dielectric constant along the a axis of a crystal has been found at 20 K, where a transition from an incommensurate modulated phase to a canted antiferromagnetic phase, as well as electric polarization along the a and b axes of the crystal induced by the magnetic field H parallel to b (H-cr similar to 40 kOe), is observed. Upon cooling the crystal in an electric field, the magnetic-field-induced electric polarization changes its sign depending on the sign of the electric field. The occurrence of the electric polarization is accompanied by anisotropic magnetostriction, which points to a correlation between the magnetoelectric and magnetoelastic properties. Based on these results, it has been stated that GdMnO3 belongs to a new family of magnetoelectric materials with the perovskite structure. (c) 2005 Pleiades Publishing, Inc.